Exmark HP or AS

What do you think would be the best mower. The one i pick will have a 52" cut.

I am looking at a Exmark HP wich is a compact size but has high class drives on it but a 23hp Kohler verticle shaft engine. Also this is an 04 model brand new priced to me at $6850. Is that a good deal?
Another option is the Exmark AS wich is a full size model a little lower class drives and has a 20hp Kohler horizontal shaft.Also this is an 04 model brand new priced to me at $6500. Is this a good deal?

Another option i kinda considered was an Encore that only has 6 hours on it that i could pick up for $4500. The reason i considered this is because i am kinda just getting started in this buisness.
THANKS FOR ANY ADVICE

i have a 2004 lazer as with 23 kohler 60 cut and it is a nice machine.according to exmark the wheel motors are dan foss that are rated just as high as parker ross,just not as much speed.they assured me the reliabilty was just as good if not better.i have had 0 problems from mine.the new 2005 52 has the 23 kohler on it,no more 20.but,dont do what i did and try to save a few hundred and cost yourself more.i bought my as and within 1 month had changed tires,airfilter,added cupholder and footassist,would have been cheaper to buy standard lazer from day one.the hp model is top of line as hoss said,as long as it says exmark on it you cant go wrong.